Well for a start, carb cleaner actually does not do what it says on the can .
Secondly the engine sounds to be out of time & out of tune + it is surging
So time for a full service
So the valve lash on both cylinders .
The remove the carb and clean according to the instructions found at
outdoor power info
It also sounds to be a touch out of time so check the timing key in the flywheel
A visual should be fine
Both slots should align PERFECTLY to make a square